JP3987139B2 - Inkjet recording head - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to an ink jet recording head that ejects ink pressurized in a pressure generating chamber as ink droplets from nozzle openings.
[0002]
[Prior art]
The ink jet recording head has a pressure generating chamber communicating with the nozzle opening, and a part of the pressure generating chamber is mechanically pressurized and deformed by a piezoelectric vibrator, or the pressure generating chamber is heated by a Joule heat generating element. The ink is pressurized by a method such as vaporizing the ink, and ink droplets are ejected from the nozzle openings.
[0003]
In order to improve the print quality in such an ink jet recording head, for example, even if a resolution of 720 dpi or more is required for both monochrome printing and color printing, the minimum pitch of one nozzle opening row is a pressure. There is a limit to reducing the nozzle opening pitch in a single row, which is limited by the width of the generating element. For this reason, a plurality of nozzle opening rows are shifted by a constant dot between each nozzle opening row. Measures are taken to increase the resolution.
That is, as shown in FIG. 16, the ink pressurizing flow path units A, B, and C each including a pressure generating chamber and a pressurizing unit are arranged in a single flow path configuration including a metal plate in which a plurality of nozzle opening rows are formed. A method is adopted in which the unit is fixed to the unit D and configured as one recording head.
[0004]
[Problems to be solved by the invention]
For this reason, it is necessary to prepare a plurality of types of ink pressurizing flow path forming units having ink discharge ports at positions facing the nozzle openings of each nozzle aperture row, which is troublesome in manufacturing and managing the ink pressurizing flow path units. There is a problem that it takes.
The present invention has been made in view of such a problem, and an object of the present invention is to share an ink pressurizing flow path unit that pressurizes ink in response to at least a drive signal, thereby providing various nozzle openings. It is an object of the present invention to provide an ink jet recording head that can accommodate an array with a small number of parts.
[0005]
[Means for Solving the Problems]
In order to solve such a problem, the ink jet recording head of the present invention includes an ink pressurizing flow path unit that forms a pressure generating chamber for pressurizing ink,
A flow passage unit having one end communicating with the pressure generation chamber, a common ink chamber for supplying ink to the pressure generation chamber, and a nozzle opening communicating with the other end of the communication hole;
An ink jet recording head configured to fix the ink pressurizing flow path unit to the flow path unit,
A plurality of the nozzle openings of the flow path unit in a row, and a plurality of nozzles formed in the same pitch P1, and the nozzle openings formed in two rows are arranged in the same row with each other;
A plurality of the nozzle openings formed in a row at the same pitch P1, and a second nozzle group shifted by P1 / 2 between the rows,
The ink pressurization flow path unit has a shape common to the first and second nozzle groups, and a plurality of the pressure generation chambers of the ink pressurization flow path unit are formed in two rows at the same pitch P1. In addition, it is formed with a P1 / 4 pitch shift so as to be biased to one side in the direction of arrangement of the pressure generating chambers of each row between rows,
The ink pressurizing flow path unit is fixed to the flow path unit so that the nozzle opening is located at a position deviated by P1 / 8 in the arrangement direction with respect to the pressure generation chamber.
[0006]
[Action]
Since the ink pressurizing flow path unit is arranged by shifting the nozzle rows composed of pressure generation chambers of the same pitch by a quarter pitch, the nozzle openings are offset by a quarter pitch with respect to the center of the pressure generation chamber. The same nozzle flow path unit can be used for various nozzle opening arrangements, simplifying the manufacturing process, improving reliability, and reducing manufacturing costs. Can be planned.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Therefore, details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 is an assembled perspective view showing an embodiment of a recording head of the present invention, and FIG. 2 is a cross-sectional view showing a structure in the vicinity of a pressure generating chamber of one ink pressurizing flow path unit 1. Reference numeral 2 in the figure denotes a first lid plate, which is composed of a zirconia thin plate having a thickness of about 10 μm. A driving electrode 5 is formed on the surface of the first lid plate so as to face a pressure generating chamber 4 described later, and PZT is formed thereon. A piezoelectric diaphragm 3 made of or the like is fixed. The pressure generation chamber 4 contracts and expands in response to the flexural vibration of the piezoelectric diaphragm 3, ejects ink droplets from the nozzle openings 28, and sucks ink in the common ink chamber 23 through the ink supply port 20.
[0008]
Reference numeral 7 denotes a spacer having a thickness suitable for forming the pressure generating chamber 4, for example, a 150 μm zirconia (ZrO 2) ceramic plate made of a through hole, and a second lid 8 described later. Both surfaces are sealed by the first lid 2 to form the pressure generation chamber 4 described above.
[0009]
Reference numeral 8 denotes a second lid, which is also connected to a later-described ink supply port 20 and a pressure generating chamber 4 on a ceramic plate such as zirconia, and the ink in the pressure generating chamber 4 is directed toward the nozzle opening 28. An ink discharge port 10 for discharging is formed and fixed to the other surface of the spacer 7.
[0010]
These members 2, 7, and 8 are formed in a clay-shaped ceramic material into a predetermined shape, and are laminated and fired to be combined into the ink pressurizing flow path unit 1 without using an adhesive. Yes.
[0011]
21 is a substrate for forming an ink supply port, which serves as a fixed substrate for the ink pressurizing flow path unit 1 and also has a metal such as non-rust steel having ink resistance so that a connection member to the ink tank can be provided. And ceramics.
[0012]
The ink supply port forming substrate 21 is provided with an ink supply port 20 for connecting a common ink chamber 23 (described later) and the pressure generation chamber 4 on one end side of the pressure generation chamber 4 in the vicinity of the recess 21a. On the other end side of the chamber 4, a communication hole 24 that connects the nozzle opening 28 and the ink discharge port 10 of the ink pressurizing flow path unit 1 is provided. Further, ink inlets 22, 22, and 22 through which ink flows from an ink tank (not shown) are formed at positions outside the region where the ink pressurizing flow path unit 1 is fixed.
[0013]
Reference numeral 25 denotes a common ink chamber forming substrate, which has a thickness suitable for forming the common ink chamber 23, for example, a plate material having corrosion resistance such as 150 μm stainless steel, and has a shape corresponding to the shape of the common ink chamber 23. A communication hole 26 that connects the hole and the nozzle opening 28 of the nozzle plate 27 and the ink discharge port 10 is formed.
[0014]
These communication holes 24 and 26 are located at the position of the nozzle opening 28 of the nozzle plate 27 and the position of the ink ejection port 10 of the ink pressurizing flow path unit 1 as shown in FIGS. A function of smoothly guiding the ink from the pressure generating chamber 4 to the nozzle opening 28 while absorbing the deviations Δd1 and Δd2, and the position of the nozzle opening 28 with respect to the center line C of the pressure generating chamber 4 is set to the pressure generating chamber. It is possible to shift by Δd3 relative to the arrangement direction.
[0015]
The nozzle plate 27 is provided with a row corresponding to a purpose, that is, a nozzle opening row suitable for monochrome high-resolution printing and a nozzle opening 28 suitable for performing color printing with a plurality of color inks. Two rows of nozzle openings belong to the ink pressurizing flow path unit 1.
[0016]
The ink supply port forming substrate 21, the common ink chamber forming substrate 25, and the nozzle plate 27 are grouped together in the flow path unit 29 by adhesive layers S and S made of a heat welding film, an adhesive, or the like. .
[0017]
By fixing a plurality of ink pressurizing flow path units 1, 1, 1 having the same structure on the surface of the ink supply port forming substrate 21 of the flow path unit 29, color printing or monochrome printing at high resolution is performed. A recording head capable of recording is configured.
[0018]
In the figure, reference numeral 14 denotes a common electrode formed on the surface of the piezoelectric diaphragm 3, and 15 denotes a flexible cable connected to an external device.
[0019]
FIG. 4 shows an embodiment of the ink pressurizing flow path unit 1 described above. In the figure, reference numerals 30, 30, 30 denote first pressure generating chambers, and 31, 31, 31 denote In the second pressure generation chambers, the first ink discharge ports 32 and 32 are arranged in parallel with each other across the center line, and communicate with the nozzle openings at fixed positions relative to the pressure generation chambers 30 and 31, respectively. , 32 and second ink discharge ports 33, 33, 33 are provided.
[0020]
The first ink discharge ports 32, 32, 32 and the second ink discharge ports 33, 33, 33 each have a pitch P1 suitable for draft printing, for example, 1/90 inch (about 0.0282 mm). Are arranged as follows.
[0021]
On the other hand, the first ink discharge ports 32, 32, 32 and the second ink discharge ports 33, 33, 33 are used for printing at a high resolution with the nearest side complementing the pitch of each ink discharge port. A suitable interval P2 in which the communication holes 24 and 26 of the flow path unit 29 can be corrected, for example, 1/360 inch (about 0.0070 mm), that is, a displacement of 1/4 of the arrangement pitch of the ink discharge ports 32 and 33. Is arranged so as to be biased toward one side.
[0022]
Thus, the ink supply port forming plate 21 constituting the flow path unit 29 is arranged by disposing the ink discharge ports 32 and 33 to one side by a pitch P1 that is 1/4 of the dot pitch suitable for draft printing. The position of the nozzle openings can be shifted by a maximum of p1 / 2 by slightly shifting the positions of the communication holes 24 and 26 of the common ink chamber forming plate 25 by, for example, about 1/360 inch each. Therefore, the same ink pressurizing flow path unit 1 can correspond to various arrangements of the nozzle openings 28 and 28 (FIG. 3).
[0023]
FIGS. 5 to 11 show an embodiment of an ink jet recording head that can be constituted by the ink pressurizing flow path unit 1 described above, in an arrangement form of nozzle opening rows and an arrangement form of ink pressurization flow paths. is there.
[0024]
FIG. 5 shows a recording head that performs monochrome printing at a pitch (P2) that is 1/4 of the arrangement pitch of the ink discharge ports 32 and 33, using the two ink pressurizing flow path units 1 that adopt the same configuration described above. It is a thing.
[0025]
The nozzle opening rows 41 and 42 belonging to the first ink pressurizing flow path unit 40 include nozzle openings 41a, 41a, 41a,..., 42a, 42a, 42a,. The nozzle opening rows 44 and 45 belonging to the flow path unit 43 have nozzle openings 44a, 44a, 44a,..., 45a, 45a, 45a,. 32 and 33 are arranged at the same pitch as the arrangement pitch P1.
[0026]
Between the two nozzle opening rows 41, 42, and 44, 45 belonging to the same ink pressurizing flow paths 40, 41, the pitch is ¼ of the arrangement pitch of the ink discharge ports 32, 33, biasing to one side. In the nozzle opening rows 41, 42, 44, 45 formed in (P 2) and belonging to the ink pressurization flow path units 40, 43, the ink discharge ports 32, 33 of the ink pressurization flow path units 40, 43 The arrangement pitch P1 is set to have a deviation of 1/2 (P1 / 2).
[0027]
Such an arrangement form of nozzle openings can be dealt with by fixing the two ink pressurizing flow path units 40 and 43 by shifting them by a half of the arrangement pitch P1 of the ink discharge ports 32 and 33. In addition, a recording head capable of monochrome printing with a resolution of 1/4 of the arrangement pitch of the ink discharge ports can be configured.
[0028]
FIG. 6 shows a case in which three ink pressurizing flow path units 50, 51, and 52 having the same configuration are configured with a recording head that performs color printing with three different shades of two colors, that is, six colors of ink. Is shown.
[0029]
The nozzle opening rows 53, 54, 55, 56, 57, 58 in each set of two rows have the same pitch (P1) as the ink discharge ports 32, 33 of the ink pressurizing flow path units 50, 51, 52, respectively, and the carriage Are arranged so as to overlap on the line in the moving direction (direction indicated by arrow A in the figure).
[0030]
Even with such an arrangement of nozzle openings, each of the ink pressurizing flow path units 50, 51, 52 is provided with nozzle openings 53 a, 54 a of the nozzle opening rows 53, 54, 55, 56, 57, 58 belonging thereto. , 55a, 56a, 57a, 58a, one of the ink discharge ports 32 is fixed by being biased in the arrangement direction of the nozzle openings of each row by 1/4 of the arrangement pitch P1 of the ink discharge ports 32, 33. It can respond by doing.
[0031]
In the above-described embodiment, the case where six color inks are ejected using six nozzle opening rows has been described. However, as shown in FIG. 7, three nozzle openings are arranged in the same arrangement form as described above. Only the columns 53, 54, and 55 are formed, and two ink pressurizing flow path units 50 and 51 are attached to these, and a total of three colors of different colors are ejected from the nozzle opening columns 53, 54, and 55, respectively. You can also.
[0032]
Furthermore, as shown in FIG. 8, one of the two nozzle opening rows 60 and 61 adopting the same arrangement form, one nozzle opening row 60 is a nozzle opening row 53, 54, 55, 56 for color printing. 57, 58 so as to coincide with the nozzle opening rows 60, 61, the ink pressurizing flow path unit 62, and the nozzle opening 60a of one nozzle opening row 60 on the lower end side of the ink discharge port 32. Further, by arranging the other nozzle opening 61a to be connected at the upper end side of the ink discharge port 33, the nozzle openings 60a, 53a, 54a, 55a, 56a, 57a of the nozzle opening rows 60, 53 to 58 are on the same line. And monochrome printing, and color printing with six color inks and black ink, and monochrome with a high resolution of 1/2 pitch of the arrangement pitch of the ink discharge ports 32 and 33. It is possible to configure the printing can printhead.
[0033]
FIG. 9 shows three ink pressurizing flow path units 70, 71, 72 having the same configuration that can be printed with the same recording head for monochrome printing and color printing, and a nozzle opening row 73 that discharges black ink. 74, the nozzle openings 73a, 73a, 73a,... And 74a, 74a, 74a,... In each row have the same pitch P1 as the arrangement pitch of the ink discharge ports 32, 33 of the ink pressurizing flow path unit 70, respectively. Although arranged, the lines 73 and 74 are shifted by 1/2 (P1 / 2) of the arrangement pitch of the ink discharge ports 32 and 33 so as to be compatible with high-density printing.
[0034]
On the other hand, the nozzle openings 75a, 76a, 77a constituting the nozzle opening rows 75, 76, 77 for discharging color ink are one row of the monochrome printing nozzle opening rows 73, 74, in this embodiment, the nozzle opening row 73. The nozzle openings 73a are arranged so as to coincide with the nozzle openings 73a and have the same pitch P1 as the ink discharge ports 32 and 33.
[0035]
For such an array of nozzle openings, the nozzle opening rows 73 and 74 for monochrome printing have ink discharge ports 32 and 33 at the ends in the direction of displacement of the array, that is, the lower side in the figure. The ink pressurizing flow path unit 70 is arranged and fixed so as to be connected on the upper side.
[0036]
On the other hand, with respect to the nozzle openings 75, 76, 77 for color printing, the direction of arrangement of the nozzle openings of the nozzle opening rows 73, 74, 75, 76, 77 in the ink pressurizing flow path unit 70 for monochrome printing. The nozzle openings 75a and 77a are arranged on the upper side of the ink discharge port 32 and the nozzle openings 76a of the nozzle opening row 76 are discharged by disposing the ink discharge ports 32 and 33 by ¼ of the arrangement pitch P1 of the ink discharge ports 32 and 33. Communication can be established below the outlet 33.
[0037]
FIG. 10 is applied to a recording head that uses three ink pressurizing flow path units 80, 81, 82 having the same configuration and performs curler printing at a high resolution that is 1/2 the pitch of the ink discharge ports 32, 33. The two nozzle opening rows 83 and 84, the nozzle opening rows 85 and 86, and the nozzle opening rows 87 and 88 belonging to the same ink pressurizing flow path unit 80, 81, 82 The nozzle openings 83, 85, 87 and the nozzle openings 84, 85, 88 are arranged so as to be located on the same line.
[0038]
The nozzle opening rows 83 and 84, the nozzle opening rows 85 and 86, and the nozzle opening rows 87 and 88 are also arranged in the same manner as the ink pressurizing flow path unit 70 shown in FIG. No. 84, nozzle opening rows 85 and 86, nozzle opening row 87, and ink discharge ports 32 and 33 are used for pressurizing ink so that they are connected at the ends in the direction of displacement of the arrangement, that is, the lower side and the upper side in the figure. This can be dealt with by fixing the flow path units 80, 81, 82.
[0039]
11 further forms nozzle opening rows 90 and 91 having the same arrangement form in the embodiment shown in FIG. 10 described above, and the nozzle opening rows 90 and 91 are the same as in the above embodiment. In this form, the ink pressurizing flow path unit 92 is fixed.
[0040]
According to this embodiment, the nozzle opening rows 90, 83, 85, and 87 are on the same line, and the nozzle opening rows 91, 84, 86, and 88 are on the same line, and are offset by P1 / 2 from each other. A recording head capable of color printing and monochrome printing with high modification can be configured.
[0041]
In the above-described embodiment, the example using the piezoelectric vibrator that flexures and vibrates as the pressure generating means has been described. However, various pressure generating means can be used.
[0042]
That is, as shown in FIG. 12, the first lid member for sealing the pressure generating chamber 4 is constituted by the single-layered piezoelectric vibration layer 101 having the common electrode 100 formed on the lower surface, and the pressure on the upper surface thereof. The individual electrode 102 may be formed in a region facing the generation chamber 4 so that only the region of the piezoelectric vibration layer 101 facing the pressure generation chamber 4 is selectively bent and displaced.
[0043]
Such a piezoelectric vibration layer 101 can be formed by various methods such as using a thin plate of a piezoelectric vibration plate, sputtering a piezoelectric material on the common electrode 100, or forming by a hydrothermal method.
[0044]
Further, as shown in FIG. 13, the first lid member is formed by the common electrode 100, and the piezoelectric vibrator 103 and the individual electrode 104 are provided on the pressure generation chamber 4 side of the common electrode 100. Accordingly, a layer suitable for elastic deformation, for example, a thin plate of zirconia can be laminated on the surface of the common electrode 100.
[0045]
Furthermore, as shown in FIG. 14, the Joule heat generating element 106 is provided on the pressure generating chamber 4 side surface of the lid member 105 that seals the spacer 7 or on the pressure generating chamber side of the other member that defines the pressure generating chamber 4. The Joule heat generating element 106 can be heated by a drive signal to vaporize the ink in the pressure generating chamber and pressurize it. In the figure, reference numeral 107 denotes a protective layer.
[0046]
Further, as shown in FIG. 15, the thick portion 108 b is partitioned by the thin portion 108 a of the lid member 108 that seals one surface of the spacer 7, and the longitudinal vibration mode is applied to the frame 111 via the fixed substrate 110. One end of the piezoelectric vibrator 109 may be fixed and the tip of the piezoelectric vibrator 109 may be in contact with the thick portion 108b. As such a longitudinal vibration mode piezoelectric vibrator, an electrode and a piezoelectric material stacked in a sandwich structure in a direction perpendicular to the displacement direction as shown in FIG. 15, or an electrode in a direction parallel to the displacement direction. And a piezoelectric material can be laminated.
[0047]
【The invention's effect】
As described above, according to the present invention, the same arrangement can be used for various arrangements of nozzle openings, and the manufacturing process can be simplified, the reliability can be improved, and the manufacturing cost can be reduced. Can do.
[Brief description of the drawings]
FIG. 1 is an assembled perspective view showing an embodiment of an ink jet recording head of the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of an ink jet recording head of the present invention with a structure in the vicinity of a pressure generating chamber of one ink pressurizing flow path unit.
FIGS. 3A and 3B are cross-sectional views showing a connection structure between a nozzle opening of a nozzle plate and an ink discharge port of an ink pressurizing flow path unit, respectively.
FIG. 4 is a diagram showing an arrangement structure of pressure generating chambers of ink pressurizing flow path units and ink discharge ports communicating with the ink pressurizing flow path unit, which is a feature of the invention.
FIG. 5 shows an arrangement form of nozzle openings and an ink pressurization flow path unit arranged correspondingly when the ink pressurization flow path unit of the present invention is applied to a recording head for monochrome printing at a high resolution. It is a figure which shows the arrangement | sequence form.
FIG. 6 shows an arrangement of nozzle openings when the ink pressurizing flow path unit of the present invention is applied to a recording head for color printing that discharges two shades of light from two nozzle openings. FIG. 6 is a diagram showing an arrangement form of ink pressurizing flow path units arranged corresponding to the above.
FIG. 7 shows an arrangement form of nozzle openings when the ink pressurizing flow path unit of the present invention is applied to a color printing recording head using ink of one color from a single nozzle opening row and a total of three colors. FIG. 5 is a view showing an arrangement form of ink pressurizing flow path units arranged correspondingly.
FIG. 8 shows an arrangement of nozzle openings when the ink pressurizing flow path unit of the present invention is applied to a recording head that performs color printing and monochrome printing using two color shades, a total of six color inks and black ink. It is a figure which shows the form and the arrangement | sequence form of the ink pressurization flow path unit arrange | positioned corresponding to this.
FIG. 9 shows an arrangement of nozzle openings when the ink pressurizing flow path unit according to the present invention is applied to a recording head for monochrome printing and color printing using black ink and three color inks. FIG. 6 is a diagram showing an arrangement form of ink pressurizing flow path units arranged corresponding to the above.
FIG. 10 shows an arrangement form of nozzle openings when the ink pressurizing flow path unit of the present invention is applied to a recording head that performs color printing at a high resolution using three color inks, and correspondingly. It is a figure which shows the arrangement | sequence form of the flow path unit for the ink pressurization arrange | positioned.
FIG. 11 shows an arrangement form of nozzle openings when the ink pressurizing flow path unit of the present invention is applied to a recording head for performing color printing and monochrome printing using black ink and three color inks. It is a figure which shows the arrangement | sequence form of the flow path unit for ink pressurization arrange | positioned correspondingly.
FIG. 12 is a diagram showing an embodiment in which the pressure generating element of the recording head of the present invention is composed of a single-layer piezoelectric material that also serves as a first lid member.
FIG. 13 is a view showing an embodiment in which the pressure generating element of the recording head of the present invention is provided in the pressure generating chamber.
FIG. 14 is a diagram showing an embodiment in which the pressure generating chamber of the recording head of the present invention is configured by a Joule heat generating element.
FIG. 15 is a diagram showing an embodiment in which the pressure generating means of the recording head of the present invention is constituted by a longitudinal vibration mode piezoelectric vibrator.
FIG. 16 is a diagram illustrating an example of a conventional multilayer ink jet recording head.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink pressurization flow path unit 2 1st cover plate 3 Piezoelectric diaphragm 4 Pressure generating chamber 5 Drive electrode 7 Spacer 8 Second cover body 9 Communication hole 9
DESCRIPTION OF SYMBOLS 10 Ink ejection port 20 Ink supply port 21 Ink supply port formation board 23 Common ink chamber 25 Common ink chamber formation board 28 Nozzle opening 29 Flow path unit

Claims (1)

An ink pressurizing flow path unit that forms a pressure generating chamber for pressurizing the ink;
A flow passage unit having one end communicating with the pressure generation chamber, a common ink chamber for supplying ink to the pressure generation chamber, and a nozzle opening communicating with the other end of the communication hole;
An ink jet recording head configured to fix the ink pressurizing flow path unit to the flow path unit,
A plurality of the nozzle openings of the flow path unit in a row, and a plurality of nozzles formed in the same pitch P1, and the nozzle openings formed in two rows are arranged in the same row with each other;
A plurality of the nozzle openings formed in a row at the same pitch P1, and a second nozzle group shifted by P1 / 2 between the rows,
The ink pressurization flow path unit has a shape common to the first and second nozzle groups, and a plurality of the pressure generation chambers of the ink pressurization flow path unit are formed in two rows at the same pitch P1. In addition, it is formed with a P1 / 4 pitch shift so as to be biased to one side in the direction of arrangement of the pressure generating chambers of each row between rows,
An ink jet recording head, wherein the ink pressurizing flow path unit is fixed to the flow path unit so that the nozzle opening is positioned at P1 / 8 in the arrangement direction with respect to the pressure generating chamber.

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